Capital gains tax calculator
CGT has two rates, and which one you pay depends on your income — gains stack on top of it. Enter the gain, your income and any losses, and see the 18%/24% split and the bill. Every figure below is editable, because these numbers move in Budgets.
Your numbers
The bill, decomposed
Effective rate: —. Estimate only — not a tax calculation you can rely on, tax advice or a personal recommendation. UK residential property gains must be reported and paid within 60 days of completion.
Assumptions and method
- 2025/26 figures, editable above: £3,000 annual exempt amount, higher-rate threshold £50,270, personal allowance £12,570 (tapered away by £1 for every £2 of income over £100,000 — the calculator models this).
- Gains are taxed at 18% within your unused basic-rate band and 24% above it — the same rates now apply to shares and residential property. Business asset disposal relief and other special reliefs are not modelled.
- "Taxable income" is stacked first: income uses up the basic-rate band before any gains do. Uses UK-wide bands (Scottish income tax bands don't change CGT, which uses UK thresholds).
- Losses reduce gains before the exemption is applied where beneficial; the calculator applies your entered losses in full, then the exemption. Carried-forward losses must have been claimed to HMRC within four years.
The system behind the numbers — what counts as a disposal, the 60-day property rule, and the legitimate ways to reduce the bill — is in capital gains tax basics. Planning a year-end sweep? See the tax year-end checklist.
Reminder: this tool is general education. It doesn't know your circumstances and isn't a personal recommendation or tax advice. For decisions, consult an accountant or FCA-authorised adviser — our toolkit shows how to find one.